1. Field of the Invention
The present invention relates to a transfer device for a press having multiple processing stages. More specifically, the present invention relates to a transfer device that conducts progressive processing on an upstream side, separates a product from a product skeleton on the way, and thereafter conducts transfer processing on a downstream side.
2. Description of the Related Art
In recent years, productivity improvements have required pressing and processing increasingly complex shapes. Additionally, manufacturers have demanded increased precision, reduced up-front equipment costs, increased processing speed, and reduced installation and operation space.
As one example of this demand, a plurality of processing steps are now frequently required for a single press. In this example, a production format calls for progressive processing on an upstream side and transfer processing on a downstream side. In this production format, a general transfer device is often used since only the transfer process is conducted with great frequency. In this type of general transfer device, a unit case houses a drive mechanism module for feed bars installed on both sides of the press. In this type of general transfer device, the unit cases that control the feed bars are installed below the feed bars creating transfer problems.
Where transfer processing frequency is low and progressive processing frequency is high, the above described general transfer device of the prior art is inadequate. Here, when a unit case is installed on an upstream side surface of the press, the distance from a material supply opening of a coil feeder to a first processing stage is long. This type of construction results in increased waste after processing is conduced. The increased waste increases costs.
Further, the long distance reduces feeding precision and negatively effects processing precision. This construction requests unit cases provided on each side of the processing area and necessitates speciality manufacturing, thus increasing costs.
Finally, since the unit cases are installed below the feed bars, space for conveyor equipment, product removal equipment, and a product receiving equipment is reduced.
It is an object of the present invention to provide a transfer device with improved productivity, reduced installation space, and reduced costs of production and purchase.
It is another object of the present invention to provide a transfer device with a unit case positioned above feed bars to increase space availability, speed processing, and reduce waste.
It is another object of the present invention to provide a transfer device with a unit case on only one side of a press to increase space, reduce costs, and increase supply and process precision.
It is another object of the present invention to provide a transfer device with feed bars supported on only one side.
It is another object of the present invention to provide a transfer device with a unit case that internalizes and protects a drive mechanism module.
It is another object of the present invention to provide a transfer device that easily accommodates a removal conveyor.
It is another object of the present invention to provide a transfer device that includes a drive mechanism combining an advance-return drive mechanism and a clamp-unclamp drive mechanism.
It is another object of the present invention to provide a transfer device that accommodates a safety sensor to prevent damage to the device upon an error in transfer.
Briefly stated, the present invention relates to a transfer device that combines an advance-return drive mechanism and a clamp-unclamp drive mechanism. The transfer device operates from only one side of a press and positions both drive mechanisms above a pair of feed bars greatly reducing all spacial constraints and costs. The feed bars operate to process a work piece along a process direction. The feed bars cantilever from the transfer device for easy use with a press and raw materials feeder or product gatherer.
According to an embodiment of the present invention, there is provided, a transfer device, conducting multiple processing steps along a process direction of a press, comprising: means for driving the transfer device, means for feeding an external workpiece along the process direction, the feeding means cantilevered from one side of the driving means, the feeding means below the driving means, the driving means including a first and second operating means, the first operating means controlling the feeding means along the processing direction, a second operating means controlling feeding means perpendicular to the processing direction, and the first and second operating means operating together whereby the transfer device processes the external workpiece from an upstream side to a downstream side and is simplified and reduced in cost and size.
According to another embodiment of the present invention, there is provided, a transfer device wherein: the driving means operates on a first side of the press, the feeding means extends below the driving means, the first operating means controls the feeding means in an advance-return motion, and the second operating means controls the feeding means in a clamp-unclamp motion.
According to another embodiment of the present invention, there is provided, a transfer device, further comprising: slider means for slidably directing the feed bars in the advance-return motion.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: a bushing, a nut, and a slider on the slider means, the slider and the bushing perpendicular to the feeding means, at least one guide shaft slidably supporting the bushing and the slider in the advance-return motion, a first ball screw shaft extending parallel to the feed bars, the nut threadably engaging the first ball screw shaft, a first drive source rotatably engages the first ball screw shaft, and the nut rotatively controls the slider in the advance-return motion whereby the external work piece processes along the process direction.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: cart means for slidably supporting the feeding means in the advance return motion and conducting the clamp-unclamp motion whereby the external work piece processes along the process direction.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: at least first and second carts in the cart means, a second ball screw shaft extending perpendicular to the feeding means between the first and second carts, the second ball screw shaft being reverse threaded at a midpoint to the process direction, a second nut on each cart, each second nut threadably engaging the second ball screw shaft, and a second drive source rotatably engaging the second ball screw shaft and rotatably controlling each cart and the feeding means in the clamp-unclamp motion whereby the external work piece processes along the process direction.
According to another embodiment of the present invention, there is provided a transfer device further comprising: an end plate affixed to an inside portion of each the cart, a spring resiliently retained between each second nut and each end plate, the second ball screw shaft extending through each end plate and each spring, a first bracket affixed to the cart opposite each end plate, and the springs providing a spring force through the second nut to the first bracket whereby the spring resiliently urges the second nut against the first bracket.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: sensor means for detecting a separation between the first bracket and the second nut, control means for controlling the press and the transfer device, the sensor means producing a signal to the control means on the separation, and the control means detecting the signal and stopping the press and the transfer device whereby damage to the drive mechanism and the feed bars is eliminated and costs are reduced.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: sensor means for detecting a failure to operate the feeding means, control means for controlling the press and the transfer device, the sensor means producing a signal to the control means on the failure to operate, and the control means detecting the signal and stopping the press and the transfer device whereby damage to the driving means and the feeding means is eliminated and costs are reduced.
According to another embodiment of the present invention, there is provided a transfer device, conducting multiple processing steps along a process direction of a press, comprising: a drive mechanism having a case, a pair of feed bars cantilevered from one side of the drive mechanism, the feed bars cantilevered in the processing direction, the feed bars extending below drive means, the drive mechanism including a first and second operating means, the first operating means operating the feed bars along the processing direction in an advance-return motion, a second operating means operating the feed bars perpendicular to the processing direction in a clamp-unclamp motion, and the drive mechanism on a first side of the press and driving the first and second operating means whereby the feed bars processes an external workpiece along the processing direction and the transfer device is simplified and reduced in size.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: a slider slidably supporting the feed bars in the advance-return motion, the slider including a bushing and a nut, the slider and the bushing perpendicular to the feed bars, at least one guide shaft slidably supporting the bushing and the slider in the advance-return motion, a first ball screw shaft extending parallel to the feed bars, the nut threadably engaging the first ball screw shaft, a first drive source rotatably engages the first ball screw shaft and the nut rotatively controls the slider in the advance-return motion whereby the external work piece processes along the process direction.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: a cart slidably supports each feed bar in the advance-return motion, a second ball screw shaft extending perpendicular to the feed bars to each cart, the second ball screw shaft being reverse threaded at a midpoint to the process direction, a second nut on each cart, the second nuts threadably engaging the second ball screw shaft, and a second drive source rotatably engages the second ball screw shaft and the second nuts rotatably control the carts and the feed bars in the clamp-unclamp motion whereby the external work piece processes along the process direction.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: an end plate affixed to an inside portion of each cart, a spring resiliently retained between each second nut and each end plate, the second ball screw shaft extending through each end plate and each spring, a first bracket affixed to the cart opposite each end plate, and the springs urging a spring force through the second nut to the first bracket whereby the second nut is resiliently urged against the first bracket.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: a sensor, a control means for controlling the press and the transfer device, the sensor detecting a separation between the first bracket and the second nut, the sensor producing a signal to the control means on the separation, and the control means detecting the signal and stopping the press and the transfer device whereby damage to the drive mechanism and the feed bars is eliminated and costs are reduced.
According to another embodiment of the present invention, there is provided a transfer device, for use in press that conducts pressing by a plurality of processing steps along a feed direction, comprising: a pair of feed bars extending parallel to a feed direction, a drive module, the drive module being of a type that drives the feed bars to conduct transporting motions of a workpiece, the drive module being of a type that supports one end of the feed bars, a unit case that internalizes the drive mechanism module, the unit case on one side surface of the press, and the unit case above the feed bars whereby the transfer device is made smaller, at a reduced cost, while increasing precision and efficiency.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: the drive module includes an advance-return drive module and a clamp-unclamp drive module, the advance-return drive module being of a type operating the feed bars along the feed direction, the clamp-unclamp drive module being of a type operating the feed bars perpendicular to the feed direction, and the drive module coordinating the advance-return drive module and the clamp-unclamp drive module whereby transfer device moves an external work piece along the feed direction.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: a slider that slidably supports the feed bars in the feed direction, a bushing on the slider, a guide shaft slidably joined to the bushing and the slider, the guide shaft slidably supports the slider along the feed direction, a first ball screw shaft, a first nut on the slider, the first nut threadably engages the first ball screw shaft, and a first drive source rotatably controlling the first ball screw shaft and the slider whereby the advance-return drive module operates and transfers the external work piece along the feed direction.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: at least one cart, the cart slidably supports each the feed bars along the feed direction, a second nut operably attached to each the cart, a second ball screw shaft perpendicular to the feed direction, the second ball screw shaft threadably engages each the second nut, the second ball screw shaft reverse threaded about a center line of the feed direction, and a second drive source rotatably controlling the second ball screw shaft and each cart whereby the clamp-unclamp module operates and transfers the external work piece along the feed direction.
According to another embodiment of the present invention, there is provided a transfer device, further comprising: an end plate, the end plate affixed to each the cart, a spring on the second ball screw shaft, the spring resiliently retained on between the each end plate and each the second nut, a bracket, the bracket affixed opposite the end plate on the cart, the springs resiliently urging each second nut against each bracket, and a sensor being of a type that detects a separation of the second nut from the bracket and sends a signal that stops the transfer device and the press whereby the transfer device and the press are protected from damage.
According to another embodiment of the present invention, there is provided a transfer device, wherein: a coil feeder is on an upstream side of the press, the transfer device is on a downstream side of the press, and the transfer device progressively transfers an external work piece from the coil feeder through the press to an offload station whereby the transfer device increases operational precision, minimizes operational costs, reduces the equipment size, and reduces waste material.
The above, and other objects, features, and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.